1. Field of the Invention
This invention relates to a process for the production of phthalazineacetic acid ester derivatives of the formula ##STR3## wherein R is (C.sub.1 -C.sub.4)alkyl.
This invention also relates to the novel compound 1-hydrazino-1,2,3,4-tetrahydro-4-oxo-phthalazineacetic acid of the formula ##STR4## which is an intermediate formed process of this invention and which is useful for the production of phthalazineacetic acid ester derivatives of formula IV. The compounds of formula IV are useful for the preparation of certain heterocyclic oxophthalazinyl acetic acids and esters thereof.